P04 Custom Code

For discussion and distribution of custom code and hacks
User avatar
antus
Site Admin
Posts: 8375
Joined: Sat Feb 28, 2009 8:34 pm
cars: TX Gemini 2L Twincam
TX Gemini SR20 18psi
Datsun 1200 Ute
Subaru Blitzen '06 EZ30 4th gen, 3.0R Spec B
Contact:

Re: P04 Custom Code

Post by antus »

Keep in mind you are using a test build, p04 is technically not yet supported. I dont want rumours to start that pcmhammer has problems with p04, before it even supports p04.
Have you read the FAQ? For lots of information and links to significant threads see here: http://pcmhacking.net/forums/viewtopic.php?f=7&t=1396
ProfessWRX
Posts: 139
Joined: Tue Oct 03, 2023 9:33 am
cars: 04 Monte SSSC
04 Tahoe
92 Trans Am
Location: AZ USA

Re: P04 Custom Code

Post by ProfessWRX »

Well to clarify for others, I was told to only bench flash P04s with pcmhammer. I’m NOT following those directions.
ProfessWRX
Posts: 139
Joined: Tue Oct 03, 2023 9:33 am
cars: 04 Monte SSSC
04 Tahoe
92 Trans Am
Location: AZ USA

Re: P04 Custom Code

Post by ProfessWRX »

Here's a hack that may or may not be useful. Instead of a hard code based switch to allow BCM to control fan turn on points or not, I've had it allow BCM to control fans when in normal mode and to lower to the PCM control temps when in performance mode.
Might allow for .000000003% fuel mileage increase.
12588500 as always:

Code: Select all

ROM:0004C146 022                 tst.b   (pTransmissionShiftPattern).w ; Test if In Performance Mode
ROM:0004C14A 022                 beq.s   loc_4C14E       ; Branch if NOT in performance mode to allow OEM BCM control of fan temps
ROM:0004C14C 022                 bne.s   loc_4C166       ; Branch if IN performance mode to allow Fan Turn on temps controlled by PCM
This is for FAN 1. All you do is copy it to the fan 2 location to do the same there. (4C350)

At some point I do plan on using actual values for normal mode instead of BCM control, but this was so easy to do it allows me to see how it is in the real world. I do think the 40 degree (F) difference in temps is too big and I'll want instead of the BCM values of 230f maybe closer to 200f.

This setup also allows for always on fans in performance mode if so desired.
kur4o
Posts: 996
Joined: Sun Apr 10, 2016 9:20 pm

Re: P04 Custom Code

Post by kur4o »

I think it is time to find the performance switch pin. I will dig for some schematics.
ProfessWRX
Posts: 139
Joined: Tue Oct 03, 2023 9:33 am
cars: 04 Monte SSSC
04 Tahoe
92 Trans Am
Location: AZ USA

Re: P04 Custom Code

Post by ProfessWRX »

kur4o wrote:I think it is time to find the performance switch pin. I will dig for some schematics.
FFFFFD17 I believe is the 'MUX' read pin.
Just need to set the correct channel when reading it.
kur4o
Posts: 996
Joined: Sun Apr 10, 2016 9:20 pm

Re: P04 Custom Code

Post by kur4o »

Maybe trace where it get saved and monitor that value.

Found some 2nd gear switch that use the same logic as 4Low/tow and performance switches. Might give you good starting point to figure all the inputs, tracing the board.

It is from 2002 v6 firebird pcm
Attachments
2nd_gear_switch_2002.JPG
2nd_gear_switch_2002.JPG (52.15 KiB) Viewed 7229 times
ProfessWRX
Posts: 139
Joined: Tue Oct 03, 2023 9:33 am
cars: 04 Monte SSSC
04 Tahoe
92 Trans Am
Location: AZ USA

Re: P04 Custom Code

Post by ProfessWRX »

kur4o wrote:Maybe trace where it get saved and monitor that value.

Found some 2nd gear switch that use the same logic as 4Low/tow and performance switches. Might give you good starting point to figure all the inputs, tracing the board.

It is from 2002 v6 firebird pcm
FFFFFDxx is the address range for the ad in/out.
kur4o
Posts: 996
Joined: Sun Apr 10, 2016 9:20 pm

Re: P04 Custom Code

Post by kur4o »

I mean when pcm read MUX it saves it somewhere as software register. Trace that software register, That manipulate different pins and monitor the software register. Usually you need to apply ground to some of it.
ProfessWRX
Posts: 139
Joined: Tue Oct 03, 2023 9:33 am
cars: 04 Monte SSSC
04 Tahoe
92 Trans Am
Location: AZ USA

Re: P04 Custom Code

Post by ProfessWRX »

I got you. I followed that software register. There’s nothing else with that pin I don’t think. I’ll double check. I’ll look around for any pins that do weird trans options.
zack4200
Posts: 80
Joined: Sat Jun 25, 2022 1:35 am
cars: 1982 Chevy Chevette 3400 LA1 swapped
1986 Chevy Chevette
1998 Chevy s10

Re: P04 Custom Code

Post by zack4200 »

kur4o wrote:Maybe trace where it get saved and monitor that value.

Found some 2nd gear switch that use the same logic as 4Low/tow and performance switches. Might give you good starting point to figure all the inputs, tracing the board.

It is from 2002 v6 firebird pcm
C2 pin21 is the same pin used for the performance shift switch in a 2000 Grand Prix
Performance Shift switch 00GP.gif

Here's a presumably stock bin I have from a GTP, it appears to have the performance switch enabled if it's worth taking a look at one where it's actually used. I would recommend only using this for reference and don't attempt flashing it with PCM Hammer, I think this one has blank parameter segment.
2000 Grand Prix GTP L67 12201791.bin
(512 KiB) Downloaded 182 times
kur40, what do you use for schematics? the Techline VM I use doesn't show the vehicle info at the bottom like yours, and that seems really convenient in yours.
Post Reply